The quantitative assessment of ligands binding to glycan targets characteristic of various pathologies, including cancer, is an essential aspect of accurate diagnosis. Unreliable quantitative assessment of ligand binding may result in misdiagnosis and consequential negative impacts on patient wellbeing. Glycan arrays have been developed for the purpose of assessing ligand binding to glycans. A glycan array consists of an array of glycans deposited, typically in the form of dots, on a substrate.
The routine fabrication of glycan arrays requires a range of putative glycan targets to be deposited [Blixt and Head (2005) High throughput glycan inicroarrays Publ. no. WO 2005/088310; Blixt et al (2004) Printed covalent glycan array for ligand profiling of diverse glycan binding proteins Proc Nat. Aca. Sc. US 101, 17033-17038].
The different glycans may be deposited with differing efficiencies and yields and therefore requires quantification before the glycan array can be used reliably and routinely in diagnosis. For automated high throughput screening the fabrication of the glycan arrays must also be consistent in terms of dot location (predetermined locus) and morphology. Variations in these parameters will result in an inability to assess ligand binding by automated systems.
The foregoing problems are particularly relevant in the context of diagnosing pathologies where the quantitative assessment of a range of glycan binding ligands is required. These problems are further exacerbated by glycan binding ligands participating in multivalent interactions with their ligand targets. It is an object of the present invention to provide an improved method of fabricating glycan arrays or to at least a useful choice.